Physical revulsion of the act of vomitting, even in comedic context.
The guy sitting in front of Debbie on the plane chummed into the blanket. Debbie had to go to the back of the plane and get out of sight of the incident because she is so chumaphobic.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.